Method of making quantum dots

A method for making quantum dots comprising:

• combining one or more highly reactive chalcogenide precursors comprising a secondary phosphine chalcogenide, one or more highly reactive metal precursors comprising a metal carboxylate, a solvent, and a seed stabilizing agent comprising a phosphonic acid at a reaction temperature above about 200° C. to form a reaction mixture where the ratio of metal to chalcogenide is in a range from about 1:1 to about 1:0.5, wherein the solvent and the seed stabilizing agent are not the same, and
• quenching the reaction mixture after nucleation by cooling the reaction mixture to a quenching temperature that is lower than the reaction temperature, resulting in seed quantum dots, and
• adding additional stoichiometric amounts of the highly reactive secondary phosphine chalcogenide precursor comprising a secondary phosphine chalcogenide and the highly reactive metal precursor comprising a metal carboxylate to the quenched reaction mixture including the seed quantum dots under conditions suitable to increase the size of the seed quantum dots to a desired size.